Rubber seal that makes a water tight seal when used with the appropriately sized bulkhead fititng. The rubber washer goes on the 'wet' side of the tank or resevoir.

Rubber seal that makes a water tight seal when used with the appropriately sized bulkhead fititng. The rubber gasket goes on the 'wet' side of the tank or resevoir. - See more at: http://www.bigalspets.com/bulkhead-fitting-gasket-1.html#sthash.Wx9AAg9u.dpuf

Rubber seal that makes a water tight seal when used with the appropriately sized bulkhead fititng. The rubber gasket goes on the 'wet' side of the tank or resevoir. - See more at: http://www.bigalspets.com/bulkhead-fitting-gasket-1.html#sthash.Wx9AAg9u.dpuf